CHICAGO (CBS) — Chicago-based United Airlines plans to fire nearly 600 workers who didn’t get their COVID-19 vaccination shots by the deadline Tuesday.

In a memo to staff, United Airlines Chief Executive Officer J. Scott Kirby, and President Brett Hart noted that more than 99 percent of U.S.-based United employees have chosen to get vaccinated – excluding those who submitted for a religions or medical exemption.

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“This is a historic achievement for our airline and our employees as well as for the customers and communities we serve. Our rationale for requiring the vaccine for all United’s U.S.-based employees was simple – to keep our people safe – and the truth is this: everyone is safer when everyone is vaccinated, and vaccine requirements work,” they wrote.

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However, 593 employees have not gotten the shot, and those employees are going to be fired.

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“This was an incredibly difficult decision but keeping our team safe has always been our first priority. The pandemic is now killing more than 2,000 people per day – a 65% increase in just the past 30 days – and the most effective way to keep our people safe, is to make sure they’re vaccinated,” Kirby and Hart wrote. “We have no greater responsibility than to ensure everyone’s safety at work. And now that nearly all of our U.S. employees are vaccinated, we take another important step forward as we emerge from the pandemic as a better, stronger United Airlines.”

CBS 2 Chicago Staff